There are currently many initiatives for developing alternative forms of generating energy or renewable energy sources. One form of renewable energy or source for electrical power generation is photovoltaics or using a light source, such as the sun to generate electricity. Solar cells are photovoltaic devices which convert light energy or photons into electrical power. Mass production of individual solar cells and concentrator solar modules require optical testing to detect defects in the solar cells or concentrator solar modules and to measure performance of the solar cells. The optical testing typically requires illuminating the solar cells using a high intensity light source. However, existing tests are typically performed on various separate test stands and at low power levels. Additionally, current testing apparatus and procedures are inefficient and make it impractical to test 100% of solar cells or concentrator solar modules. Accordingly, there is a need for a more efficient and reliable apparatus and method for testing solar cells.